


Doppelganger

by GoldenFeathers



Category: Undertale (Video Game)
Genre: Dubious Consent, Dubious Morality, Incest, M/M, One-Sided Attraction, Pining, Shapeshifting, Sibling Incest, dubcon, flowey on his bullshit, i mean it's flowey
Language: English
Status: In-Progress
Published: 2019-11-21
Updated: 2019-11-21
Packaged: 2021-02-25 22:42:22
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,843
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21513223
Author URL: https://archiveofourown.org/users/GoldenFeathers/pseuds/GoldenFeathers
Summary: “I WANT YOU TO KISS ME BROTHER. IN A VERY NON-BROTHERLY WAY.”Flowey was inches from his face, but was cruelly not moving closer or making any of his threats a reality. Mercifully. Mercifully he wasn't moving closer. Sans saw the expression shift out of his peripheral and looked up at the mask, expecting the illusion to be broken with one of Flowey's trademark cruel grins.Instead, he was nose to nose with Papyrus's pleading, open, hopeful face.“Sans… Please?”
Relationships: Asgore Dreemurr/Sans, Flowey/Sans (Undertale), Papyrus/Sans (Undertale)
Comments: 2
Kudos: 33





	Doppelganger

Flowey caught him alone in Waterfall this time. Sans had seen it coming, it had been too long since he was last harassed. Flowey was trying to get him to react by doing impressions this time. Sans was just judging him honestly. His Grillby needed work, badly. Flowey went for an Asgore, following his usual script of insults, deprecation, blows at his ego and exceptionally lewd suggestions. Flowey did an eerily good Asgore impression, but man he needed new material. It was almost getting boring, especially considering the ammo Sans had of having actually slept with the monster. He wasn't sure why Flowey was so connected exactly though, so he saved that shot for later. Flowey was getting peeved at the lack of response, so he went for his last resort, the one that always pushed sans's buttons.  
His face morphed into a perfect replica of Papyrus, haloed with yellow petals.  
“USELESS AS USUAL, BROTHER. WILL YOU EVER DO ANYTHING WORTHWHILE?”  
Sans felt a pang and then smashed it down, trying to smother the feeling with his frustration at Flowey. He was glad his poker face was well practiced.  
“HONESTLY, IT’S NO SURPRISE YOU CAN’T MAKE ME HAPPY. ALL YOU DO IS GET DRUNK OR HIGH. YOU NEVER EVEN HAVE TIME FOR YOUR DEAR, SWEET BROTHER! DO YOU EVEN CARE ABOUT ME?”  
“Needs workshoping.”  
“OH, WOULD YOU PREFER I GO STRAIGHT TO PLEADING? PLEASE, PLEASE DON’T LET HIM KILL ME AGAIN SANS! YOU PROMISED YOU’D PROTECT ME! YOU PROMISED YOU WOULD KEEP ME SAFE.”  
Ouch. Sans backed up a step without thinking.  
“THAT’S OKAY, BROTHER. YOU COULD MAKE IT UP TO ME WITH A KISS! DON’T YOU WANT TO KISS ME SANS? COULD YOU EVER SAY NO TO ME, EVEN IF YOU DIDN’T?” Flowey leaned forward, eagerly studying Sans’s face. Sans just glared.  
“WOULD YOU STOP ME IF I KISSED YOU? WOULD YOU STOP ME IF I TOUCHED YOU? ARE YOU EVEN CAPABLE OF STOPPING SOMEONE FROM TOUCHING YOU, SANS?”  
Sans backed up another step, confused, and confused as to why he was confused. He didn’t respond, just kept glaring.  
Flowey grinned and went for what seemed to make sans most uncomfortable, which was sexual comments in his astonishingly accurate Papyrus impression. Sans absently thought Pap and Flowey must be better friends than he realized. He had Pap’s mannerisms down to a T.  
Sans backed up another few steps, his face a delicious mix of discomfort and anger, and Flowey pushed in further, fighting to keep a Papyrus-esque expression.  
“OH COME ON SANS, YOU'RE SUCH A SLUT ANYWAYS. WHAT DIFFERENCE DOES IT MAKE? A COCK IS A COCK, AFTER ALL. DON'T YOU WANT MINE?”  
Sans was backed up against the wall now, breathing hard. Papyrus would never say that. Papyrus would never say that.  
“DON’T YOU WANT ME, SANS? YOU SAID I WAS HANDSOME. WERE YOU LYING TO ME AGAIN?”  
He was trying his best not to look at the mask, and that's all it was, he reminded himself, a mask Flowey was wearing. And an absurdly accurate vocal impression, right down to the somewhat whimsical and unpredictable inflections. Sans's soul was in his throat and he was alight with a mix of anger and confusion and something much hotter, much deeper, that was clouding his skull up. Sans looked away.  
“I WANT YOU TO KISS ME BROTHER. IN A VERY NON-BROTHERLY WAY.”  
Flowey was inches from his face, but was cruelly not moving closer or making any of his threats a reality. Mercifully. Mercifully he wasn't moving closer. Sans saw the expression shift out of his peripheral and looked up at the mask, expecting the illusion to be broken with one of Flowey's trademark cruel grins.  
Instead, he was nose to nose with Papyrus's pleading, open, hopeful face.  
“Sans… Please?” He smiled slightly, hopefully, cocking his head to the side the slightest amount, the way he did when he thought Sans would look away and wanted to retain his line of sight for even a millisecond longer. The world melted to the background and sans gently cupped the side of Pap's face, stroking his cheekbone before tenderly pressing their faces together. Pap was still for just a moment, then he was gently leaning into the kiss, cautious and testing. Sans led, leaning in too, stroking the side of his face and deepening the kiss. Papyrus made a soft sound, a kind of breathy sigh, and Sans felt it shoot through his whole body with fire, almost answering it with a moan. He deepened the kiss, feeling Pap enthusiastically respond, and holy shit he couldn't believe how this felt, the sheer power of it surging through him threatening to knock him over. He cracked open his jaw and summoned a tongue, prodding, and Pap opened his mouth for him almost needily. Sans slipped his tongue inside, tipping his head forward and angling deep. He tasted pollen and sap and. wait. wait a minute  
Sans pulled away and almost moaned at what he saw, Papy's face flushed and his mouth still hanging open, a line of drool connecting their faces, both panting.  
“flowey.”  
Papyrus closed his mouth and smoothed out his expression, then looked at him, contemplative. Sans searched Flowey's face for any tell, but where the ecstatic malice or disturbed glee was he saw only deep thought.  
“WE… DON'T HAVE TO STOP JUST YET” Papyr- no, Flowey said, and the timber of his impression almost brought Sans to his knees. He couldn't deny this was so, so close to living one of his darkest fantasies. He… He really wanted this. He wanted Pap. He wanted to taste him and smell him and feel every inch of him, inside and out.  
He wanted to hear Papyrus moan his name.

And he knew how he could get that.

Sans dove back in, catching Pap a bit off guard, as he kissed him, gently at first and then with more and more heat. Maybe he was using a weird collonge. Maybe he just ate a bunch of spices with Undyne. He experimentally lapped at the side of Pap's face. The texture of the false bone was perfect, solid and sturdy except in the places active and magically malleable. Sans… bought it. Pap had gotten coated in golden flower tea, and maybe a bit of bitter honey. He moaned slightly and started pressing kisses and small nips along Pap's perfect jawline, up to the junction of his zygomatic arch and his mandible, stopping to flick his tongue over Pap's ear. His breath was commin in ragged bursts and he wanted so much more. He couldn't remember why he hadn't dragged Papy closer, why he hadn't pressed their chests together so he could feel his love's breath in ragged bursts, feel his mate's soul thumping. Sans reached forward, cupping the base of Papy's neck. His fingers explored it, and Sans pulled back a bit at the texture, like bark. A half formed skeletal body out of sturdy branches and vines was trembling in front of him.  
It wasn't nearly as beautiful as the real thing, Sans assessed. The femurs weren't quite sturdy enough, didn't have the same elegant swoop, and the ribcage wasn't broad enough, his illium lacking the rugged yet graceful curve. Sans fought a mixture of disappointment and relief. Flowey had no clue what Papyrus looked like under his battle body. That was good, that was one horror less for Pap to deal with. And this would do, Sans decided.

He could pretend. He was good at pretending.

Papyrus's eyes opened slightly, his mouth still open and his cheeks flushed.  
“SANS…” he moaned breathily. Sans felt the last shreds of his self control snap.  
He'd pinned Pap against the cavern wall before he registered moving, kissing him hungrily, words spilling out of him every time he pulled himself away.  
“god, pap” a firmer kiss, “i love you so much” he tilted his head, “i love you so fucking much” he flicked his tongue lightly into Papy's mouth, “you're so fucking beautiful” he rolled his hips forward, “you’re so perfect” his hands were everywhere, “fuck i love you” sliding along his ribcage and back, “i love you so much” he dug his thumb into an iliac crest and Papyrus moaned.  
“SAA- AANSSS…”  
“oh god, papyrus.”  
He felt the other's hips buck against his, and he languidly slid his hand along the curve of his ilium to his spine. Pap's breath hitched and he wrapped his arms around sans's neck.  
“god i love you”  
He slid his hand lower.  
“a-AH!! SANNSSS!”  
It was the most powerful aphrodisiac sans had ever fucking encountered and all thoughts other than pleasing him, makin him feel so good, makin him make more of those sounds, trickled out of his head leaving only single-minded desire. He watched Pap with laser focus as he moved his hand even lower, brushing over his sacrum. Pap arched and cried out, his eyes falling closed and his chest heaving. Sans drank in the sight. That was because of him. Pap looked that blissed out because of him. He gently traced his finger up and down the sensitive sheet of bone, studiously avoiding the holes. Pap was gasping and making little keening sounds and sans couldn't look away from that gorgeous expression, god that was so fucking good. He dipped a finger gently into one of the sacral holes and suddenly Pap bucked into his hand, whining, leaning forward, pressing against his face. Sans pressed their cheeks together as he moved his hand, then turned and started softly kissing up and down his face. God, his browline was scrunched in pleasure, his eyes squeezed shut, cutely crinkling the bone around the corners of his sockets. Sans kissed and nibbled at his cheekbone, savoring the graceful swoop of the bone. He was lightly pumping his fingers into Pap's sacral foramen, gently prodding through the holes. Pap was letting out breathy moans, hitching and gasping as though unable to control himself. Sans realized he'd been whispering for a while, quietly muttering a stream of "i love you", "fuck yeah papyrus", "so fucking good", "love you so much."  
Pap shifted slightly and sans saw him glance down at sans's pelvis. he was rock hard and bucking his hips in the air a bit, nearly uncontrollably. Pap shifted slightly against the wall and sans curled his fingers, making him gasp. but then he felt pap's leg come between his and just barely graze the bottom of his pelvis. he moaned, pressing his face against papyrus's so they were cheek to cheek.  
"Sans… Please, I want you, please," Papyrus's breath was on his ear and the side of his face and his voice sounded wrecked and so, so desperate. Sans had his shorts pulled down past his dick and was lining himself up with Pap's entrance before he realized what he was doing. his pelvic girdle didn't have any magic summoned, but sans was experienced in doing it this way too. a drop of precum landed on Pap's sacrum and his breath hitched.

**Author's Note:**

> im planning on finishing this but im unmotivated and overworked so idk when


End file.
